Socmed is limited
Social media sites don't have all the features needed, and often these are added only when there is public demand.
Websites outrank social media pages in SEO
If you search for, say "coffee shop", first-page result will show articles about coffee shops, not a link to a social media page. In fact, almost every organic listing that shows up is an article featured on a website.
Websites are universal
If you happen to only run a LinkedIn profile and not much else, remember that viewing a LinkedIn business page requires one to have an account, and not everyone has a LinkedIn account. In contrast, websites are accessible by everyone, and won't ask visitors to sign up just so they can view and gain access to your page.